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Finding the Fourth Proportional to 780.43, 1,162.15 and 771.80

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Solution

The fourth proportional to 780.43, 1,162.15 and 771.80 is: 1,149.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.43 : 1,162.15 = 771.80 : x
  2. Step 2: Convert to fraction form
    780.43/1,162.15 = 771.80/x
  3. Step 3: Cross multiply
    780.43x = 1,162.15 × 771.80
  4. Step 4: Simplify right side
    780.43x = 896,949.79
  5. Step 5: Solve for x
    x = 896,949.79/780.43
  6. Step 6: Final answer
    x = 1,149.30

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.